Low profile contact for insertion in printed circuit board

ABSTRACT

A low profile contact means stamped from a section of flat stock material and comprising an incomplete cylindrical portion having a C-shaped cross-sectional configuration and further having a flanged portion at one end thereof. A terminal pin extends from the other end of said cylindrical portion. The contact is inserted through an aperture in a printed circuit board with the flanged portion seated on the surface of said circuit board. A tang formed from the cylinder wall extends downwardly into said cylindrical section and towards the gap created by the incomplete cylindrical section. A male pin inserted in said cylindrical section will be pressed by said tang into said gap in said cylindrical section and against the wall of the printed circuit board aperture.

United States Patent [191 Coller et al.

[ Dec. 31, 1974 LOW PROFILE CONTACT FOR INSERTION IN PRINTED CIRCUITBOARD [75] Inventors: James Ray Coller, Mechanicsburg;

Robert Franklin Cobaugh, Elizabethtown, both of Pa.

[52] [1.5. CI. 339/17 C, 339/244 R, 339/258 R [51] Int. Cl HOSk l/04,HOlr 13/12 [58] Field of Search 339/17 R, 17 C, 244 R, 339/255 R, 256 R,256 RT, 256 S, 256 T,

258 R, 258 A, 258 RR, 258 T, 258 TC, 259

R, 262 R, 262 P, 262 RR 1,336,574 7/1963 France 339/17 R PrimaryExaminer-Roy D. Frazier Assistant Examiner-Lawrence J. Staab Attorney,Agent, or FirmAMP Incorporated [57] ABSTRACT A low profile contact meansstamped from a section of flat stock material and comprising anincomplete cylindrical portion having a C-shaped cross-sectionalconfiguration and further having a flanged portion at one end thereof. Aterminal pin extends from the other end of said cylindrical portion. Thecontact is inserted through an aperture in a printed circuit board withthe flanged portion seated on the surface of said circuit board. A tangformed from the cylinder wall extends downwardly into said cylindricalsection and towards the gap created by the incomplete cylindricalsection. A male pin inserted in said cylindrical section will be pressedby said tang into said gap in said cylindrical section and against thewall of the printed circuit board aperture.

5 Claims, 3 Drawing Figures LOW PROFILE CONTACT FOR INSERTION IN PRINTEDCIRCUIT BOARD BACKGROUND OF THE INVENTION This invention relatesgenerally to a low profile insertion type contact and more particularlyto a low profile contact which is inserted through a hole in a printedcircuit board and which is fabricated by a stamping process from acontinuous supply of flat stock material rather than being fabricated byconventional screw machine techniques.

A type contact in wide use today with printed circuit boards is acontact having a pin at one end and a female receptacle at the other.This contact is inserted through a hole in a printed circuit board sothat the female portion is engageably secured to the wall of the hole inthe printed circuit board and the pin portion thereof extends throughthe printed circuit board and forms a terminal post for one or morewires. Such wires can be connected to the terminal post in the wellknown wraparound means or any other suitable methods for securing a wireto a post. Components having male pin type terminals are then mounted onthe circuit board by insertion of said male pins into the female portionof the inserted contacts.

In certain applications such as hand calculators, where space is at apremium, it is desired that the female portion of insertion typecontacts have a low profile, i.e., the receiving opening of said femaleportion should be nearly flush with the surface of the printed circuitboard. As a result of such low profile contacts components mountedtherein will also be positioned close to the surface of the printedcircuit board, thereby conserving space. Up to the present time such lowprofile insertion type contacts have been fabricated by screw machinetechniques. Moreover, in most types of screw machine fabricated contactsit has been necessary to insert a spring in the female portion of thecontact in order to make the structure capable of retaining 21 male pinsubsequently inserted therein.

Furthermore, in contacts fabricated by a screw machine technique, thefemale portion consists ofa closed cylindrical section having verylittle spring, or give. Thus, the tolerances of both the diameter ofsuch female portions and also the diameter of the hole in the printedcircuit board must be maintained within close limits. If the hole in theprinted circuit board is too large compared to the diameter of thefemale portion of the contact, neither a good mechanical or a goodelectrical contact will be made when the contact is inserted therein. Onthe other hand if the aperture in the printed circuit board is toosmall, the plating on the walls of the printed circuit board hole isvery apt to be scraped away when the contact is inserted therein, thusproducing a poor electrical contact.

A further disadvantage of the screw machine type insertion contact liesin the fact that not one, but two, electrical contacts must be made.Firstly, the male pin inserted therein must make good contact with thefemale portion of the insertion contact, and secondly, the insertioncontact must make good electrical contact with the wall of the printedcircuit board hole since the male pin does not make direct physicalcontact with the wall of said hole.

OBJECTS OF THE INVENTION It is a primary object of the invention toprovide an inexpensive, low profile female contact for insertion througha printed circuit board.

A second aim of the invention is to provide an inexpensive, low profilecontact having a post at one end and a cylindrically shaped femalereceptacle at the other end, with said female receptacle having acapability of being radially compressed to enable its use in printedcircuit board holes having a relatively wide range of diametertolerances.

It is a third purpose of the invention to provide a low profile contactmeans consisting of a pin and a cylindrically shaped female receptacleinsertable through a hole in a printed circuit board and consisting of asingle element fabricated by stamping from flat stock material.

A fourth object of the invention is an inexpensive, low profile contactmeans having a cylindrically shaped female receptacle insertable througha printed circuit board hole and capable of receiving a male pintherein, and in which said male pin makes contact simultaneously withthe female receptacle and the wall of the printed circuit board hole.

A fifth aim of the invention is the improvement generally of insertiontype contact means for use in printed circuit boards.

STATEMENT OF INVENTION In accordance with the invention there isprovided a low profile contact means consisting ofa single element whichis stamped from a section of a continuously fed supply of flat stockmaterial, and having a female receptacle portion thereof which engagesthe wall of a hole in a printed circuit board through which the contactis inserted. This female portion of the contact is constructed to begenerally cylindrical in configuration but open over one arcuate sectionso that it has a resultant C-shaped cross-sectional configuration. Thetop portion of this cylindrical portion of the contact is flaredoutwardly to form a flange which seats on the top surface of the printedcircuit board around the perimeter of the hole in said circuit board.The cylindrical portion further comprises a tang or finger which isstampformed from a portion of the cylinder wall and which extendsoutwardly from said cylinder wall into the center portion of thecylindrical portion towards the open portion of the cylinder wall. Thus,when a male pin is inserted into the cylindrically shaped female portionof the contact means, said pin will be forced by said tang against thatportion of the wall of the printed circuit board aperture which isexposed through the open portion of the contact means cylinder wall.Also attached to said cylindrical portion of the contact means is a postto which a conductor can be secured by any suitable technique, such aswire-wrapping.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other objectsand features of the invention will be more clearly understood from thefollowing detailed description thereof when read in conjunction withdrawings, in which:

FIG. 1 is a perspective view of the invention and specifically shows twoof contact means inserted through a printed circuit board, with one ofthe contact means being broken away to show the details thereof;

FIG. 2 is a plan view of two of the contact means with connectingcarrier strips also shown; and

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, the two contactmeans 11 and 12 are shown inserted through holes 17 and 18 in theprinted circuit board 10, of which board only a small section is shown.Each of the two contact means 11 and 12 are identical. However, contact12 is shown with a portion of the printed circuit board broken away todisclose the details of said contact means 12. The contact means 12 canbe seen to consist of three principal parts, including a pin 23, asemicylindrical section 31 with a flared-out flange 14 formed at the topthereof, and a tang 13, which is formed from a section of the wall ofcylindrical section 31.

The contacts 11 and 12 are secured at their upper end to a commoncarrier strip 22 which has a plurality of holes 19 formed therein. Suchholes 19 are utilized with appropriate means, such as a sprocket wheel,to drive-feed a strip of flat stock material (not shown) from which thecontacts 11 and 12 are formed, through appropriate stamping and cuttingdies.

In use, the contact means 11 and 12 are inserted through apertures 17and 18 in a printed circuit board 10. Each of the apertures 17 and 18 inthe printed circuit board segment 10 can be prepared with a previouslyinserted metal tubular section 28, or alternatively the element 28 canrepresent a conductive platedthrough coating on the inner walls ofapertures 17 and The flange portions 34 and 14 of contact means 11 and12 seat upon the surface of printed circuit board 10 to thereby providea low profile female contact means which can receive male pin terminals.

Such male pin terminals (not shown), when inserted into the femalereceptacles of contacts 11 and 12, are forced against the walls of theaperture holes by means of the tangs such as tangs 16 and 13. Morespecifically, the cylindrical portions 30 and 31 of the contacts 11 and12 do not extend arounda complete 360 sweep, but rather are C shaped andleave a portion of the printed circuit board aperture walls exposed tothe inner portion of the cylindrical receptacles 30 and 31. The tangs l6and 13 are formed to extend towards this exposed portion of the aperturewalls so that when a male pin terminal (not shown) is inserted in thecylindrical receptacles 30 or 31 the tangs 16 and 13 will force saidpins against the walls of the apertures, thereby creating a directelectrical contact between the inserted male pins and the aperturewalls, as well as establishing a direct electrical contact between theinserted pins and the contact means 11 and 12.

The outside diameter of the cylindrical portions 30 and 31 of contactmeans 11 and 12 are fabricated to be slightly greater than the diameterof the printed circuit board holes 17 and 18 plus a predetermineddiameter tolerance for said holes. Because the cylindrical portion doesnot define a completely closed cylinder, it can act in the nature of aspring when inserted in a smaller diameter printed circuit board hole.The cylindrical portions of the contact means will be radiallycompressed by the smaller diameter holes of the printed circuit board toestablish a continuous outwardly directed spring force against the sidesof the aperture walls, thereby establishing both a good mechanicalcontact and a good electrical contact with said aperture walls.

Referring now to FIG. 2 there is shown a plan view of the two contactmeans 11 and 12 when they are not inserted in a printed circuit board.Also shown in FIG. 2 is the carrier strip 22, as well as a secondcarrier strip 20 which is secured to the ends of the pins 23 and 24 ofthe two contact means 12 and 11. Before gang insertion of pins 23 and 24into appropriate holes in a printed circuit board, the lower carrierstrip 20 must first be separated from the contacts. However, the uppercarrier strip 22 is not so separated, thereby permitting gang insertioninto a row of holes in a printed circuit board to be effected quicklyand efficiently since alignment of the pins with the holes is maintainedby the carrier strip 22. After insertion of the contacts the carrierstrip 22 is separated from the contacts.

Referring now to FIG. 3, it can be seen that tang element 13 extendsinto the gap created as a result of the cylindrical portion 31 of thecontact 12 not extending around through a complete 360 sweep.

It is to be specifically noted that carrier strips 20 and 22 and thecomplete contact means attached thereto, such as contact means 11 and12, are fabricated from a single, continuously fed supply of flat stockmaterial. No other parts are needed. Such flat stock material is fed toone or more work stations (not shown) where the proper stamping, cuttingand cold working is accomplished to form the continuous strip ofcontacts and carriers.

It is to be understood that the form of the invention shown anddescribed herein is but a preferred embodiment thereof and that variouschanges in configuration and proportions can be made without departingfrom the spirit and scope thereof.

What is claimed is:

1. The combination of a stamped, single element, low profile contactinserted through an aperture in a circuit board and comprising:

a partially completed cylindrical section in which a gap parallel to theaxis of said cylindrical section exists in the wall thereof;

a flange portion formed around the rim of one end of said cylindricalsection and constructed to form a seat for said contact when saidcontact is inserted in said circuit board;

said flange portion being flared outwardly and upwardly from saidcylindrical section to facilitate entry of a mating male contacttherewith; and

an elongated element formed from the wall of said cylindrical sectionand extending inwardly into the space defined by said cylindricalsection and into said gap;

said gap being sufficiently wide to enable entry of said elongatedelement therein.

2. The combination in accordance with claim I in which said circuitboard aperture has walls of conductive material; and

in which the outside diameter of said cylindrical section is slightlygreater than the diameter of said ap-.

erture to ensure good electrical contact between said cylindricalsection and the walls of said aperture when said cylindrical section isinserted in said aperture.

3. The combination in accordance with claim 1 in which a portion of saidelongated element is positioned within said gap in the wall of saidcylindrical section to force said male pin inserted in said aperturethrough entry of a mating male contact therein; said gap and intopressure contact with the wall of said an elongated element formed fromthe wall of said aperture in said circuit board. cylindrical section andextending across the inte- 4. A single element low profile contactconstructed rior of said cylindrical section towards said gap; entirelyfrom a section of flat stock material and which 5 said gap beingsufficiently wide to enable entry of is adapted for insertion through anaperture in a circuit said elongated element therein; and board andfurther, which comprises: terminal means attached to the other end ofsaid cya partially completed cylindrical section in which a lindricalsection.

gap exists in the wall thereof; 5. A low profile contact in accordancewith claim 4 a flange portion formed around the rim of one end of 10 inwhich a portion of said elongated element is posithe said cylindricalsection and constructed to form tioned within said gap in the wall ofsaid cylindrical seca seat for said contact when it is inserted throughtion to force said male contact inserted in said aperture said circuitboard; through said gap and into pressure contact with the said flangeportion being flared outwardly and upwall of said aperture in saidcircuit board.

wardly from said cylindrical section to facilitate

1. The combination of a stamped, single element, low profile contactinserted through an aperture in a circuit board and comprising: apartially completed cylindrical section in which a gap parallel to theaxis of said cylindrical section exists in the wall thereof; a flangeportion formed around the rim of one end of said cylindrical section andconstructed to form a seat for said contact when said contact isinserted in said circuit board; said flange portion being flaredoutwardly and upwardly from said cylindrical section to facilitate entryof a mating male contact therewith; and an elongated element formed fromthe wall of said cylindrical section and extending inwardly into thespace defined by said cylindrical section and into said gap; said gapbeing sufficiently wide to enable entry of said elongated elementtherein.
 2. The combination in accordance with claim 1 in which saidcircuit board aperture has walls of conductive material; and in whichthe outside diameter of said cylindrical section is slightly greaterthan the diameter of said aperture to ensure good electrical contactbetween said cylindrical section and the walls of said aperture whensaid cylindrical section is inserted in said aperture.
 3. Thecombination in accordance with claim 1 in which a portion of saidelongated element is positioned within said gap in the wall of saidcylindrical section to force said male pin inserted in said aperturethrough said gap and into pressure contact with the wall of saidaperture in said circuit board.
 4. A single element low profile contactconstructed entirely from a section of flat stock material and which isadapted for insertion through an aperture in a circuit board andfurther, which comprises: a partially completed cylindrical section inwhich a gap exists in the wall thereof; a flange portion formed aroundthe rim of one end of the said cylindrical section and constructed toform a seat for said contact when it is inserted through said circuitboard; said flange portion being flared outwardly and upwardly from saidcylindrical section to facilitate entry of a mating male contacttherein; an elongated element formed from the wall of said cylindricalsection and extending across the interior of said cylindrical sectiontowards said gap; said gap being sufficiently wide to enable entry ofsaid elongated element therein; and terminal means attached to the otherend of said cylindrical section.
 5. A low profile contact in accordancewith claim 4 in which a portion of said elongated element is positionedwithin said gap in the wall of said cylindrical section to force saidmale contact inserted in said aperture through said gap and intopressure contact with the wall of said aperture in said circuit board.